Element Operators

linq58: First - Simple

//c#
public void Linq58() 
{ 
    List products = GetProductList(); 
 
    Product product12 = ( 
        from p in products 
        where p.ProductID == 12 
        select p) 
        .First(); 
  
    ObjectDumper.Write(product12); 
}

linq59: First - Condition

//c#
public void Linq59() 
{ 
    string[] strings = { "zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine" };
  
    string startsWithO = strings.First(s => s[0] == 'o'); 
  
    Console.WriteLine("A string starting with 'o': {0}", startsWithO); 
}

linq61: FirstOrDefault - Simple

//c#
public void Linq61() 
{ 
    int[] numbers = { }; 
  
    int firstNumOrDefault = numbers.FirstOrDefault(); 
  
    Console.WriteLine(firstNumOrDefault); 
}

linq62: FirstOrDefault - Condition

//c#
public void Linq62() 
{ 
    List products = GetProductList(); 
  
    Product product789 = products.FirstOrDefault(p => p.ProductID == 789); 
 
    Console.WriteLine("Product 789 exists: {0}", product789 != null); 
}

linq64: ElementAt

//c#
public void Linq64() 
{ 
    int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 }; 
  
    int fourthLowNum = ( 
        from n in numbers 
        where n > 5 
        select n) 
        .ElementAt(1);  // second number is index 1 because sequences use 0-based indexing 
 
    Console.WriteLine("Second number > 5: {0}", fourthLowNum); 
}